<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      const obj = {
        name: 'zs',
        age: 18,
      }
      let a = 'age'
      console.log(obj.name)
      console.log(obj['name'])
      console.log(obj[a]) // ==>  obj['age']
    </script>
  </body>
</html>
